选准代表物质 开辟探究路径 培育核心素养——“卤代烃”的创新教学

在卤代烃的课堂教学实践中，选定1-溴丙烷为代表物，依据化学键理论并结合模型认知、实验探究等方式创新设计课堂教学，既规避和弥补按某些教材教学带来的尴尬与不足，又能突破教学难点（卤代烃消去反应原理），更能培育"宏观辨识与微观探析""证据推理与模型认知""科学探究与创新意识""科学态度与社会责任"等学科核心素养。     

化学学习中“电解质”概念相异构想的跨年级研究

运用自编的二段式诊断测验,对10到12年级的529名中学生进行了“电解质”概念相异构想的问卷测查。对测查数据运用Rasch模型进行分析,结果显示不同年级中学生有关“电解质“的相异构想存在着差异。依据SOLO分类标准对中学生“电解质”的相异构想进行了分类,并借助课堂观察和访谈对不同年级中学生“电解质”相异构想的来源进行了分析。     

基于Rasch模型的化学核心概念理解测量研究

学科概念的理解程度直接决定着学习目标的达成与否,国内外科学教育标准均把培养学生科学核心概念理解能力作为提高科学素养宗旨的主要途径。在探查和诊断学生对化学核心概念理解能力上,既需要考虑具体的学科概念,也需要考虑到学生当前的认知阶段。尽管有很多工具可用来诊断学生的概念理解能力,与其他诊断工具相比,二段式诊断工具具有精确性和具体性,且可以大规模地推广和应用。同时,在对诊断方法有效性检验上,Rasch测量模型理论比经典测量理论更具针对性和有效性。以化学学科中"溶液中的离子平衡"概念为例,阐述如何利用二段式诊断方法来设计化学核心概念理解的测量工具,并进一步实证研究如何利用Rasch测量模型理论来对测量工具进行质量检验与修改。     

化学键概念的学生调研及教学策略

化学键是中学化学中的一个重要概念。通过学生调研,发现学生在学习化学键之前对物质的形成有一定的认识经验,头脑中也存在不少错误认识,这将成为他们学习化学键概念的严重障碍。在教学设计中,教师应根据学前调研的信息,从学生的认识出发,采用切实可行的教学策略,及时纠正学生学习前头脑中的错误概念,引导学生顺畅地达成对化学键概念的准确认识。     

“化学键”学习前学生的前概念调查与转变策略探析

通过调查学生在学习“化学键”前关于本概念的各种认识,发现学生“化学键”前概念的产生原因：（1）日常生活经验影响;（2）理科学习经验影响;（3）认知图式仍然在宏观层面。在此基础上提出了进行“化学键”概念转变教学的5条策略。     

医用有机化学波谱分析绪论部分的教学研究

概述了问题导向式的研究型教学设计在医科院校"医用有机化学"课程中有机波谱分析章节的应用情况。该部分内容具有学生"难学" "难考" ，教师"难教"的教学特点。基于此，通过层层设问、循序解答的授课方式，结合丰富的应用示例，进行有机波谱分析核心概念（绪论）的理论教学。结果表明，该教学方法可有效提高学生学习兴趣，降低学习难度，使学生在有限的学时内掌握有机波谱分析的基础理论与核心概念，为后续识谱、解谱能力的培养夯实基础。     

基于高中生概念认知水平的定量化能力测评研究

采用定量、定性相结合的研究方法探究基于高中生概念认知水平的定量化能力水平特征。研究结果表明,建构的定量化能力框架符合学生认知水平发展,编制的测量工具经Rasch模型检验具有良好的信度和效度;高中生定量化能力呈“U”型分布;数学、化学学科学业水平与学生定量化能力呈显著正相关;中、低能力水平学生在选择题、建构反应题上表现有显著差异。     

基于元认知理论的化学键概念应用问卷开发

为了测量高一学生在应用化学键概念时元认知的参与程度,设计了基于元认知理论的化学键概念应用问卷。该问卷包括共价键和离子键2个基本概念,每个基本概念包括5道封闭式题目。在每道封闭式题目之后追加2个开放式任务,用于测量学生应用化学键概念时元认知知识和元认知监控的参与程度。对已经学过化学键概念的高一学生进行测试后的调查数据分析表明,该问卷具有较高的内部一致性,并具有较好的信度和效度指标。因此,该问卷可作为一种测量学生应用化学键概念时元认知参与程度的工具,并具有较强的应用价值。     

基于Rasch模型的高中化学学科核心素养测评研究——以“变化观念与平衡思想”为例

以《普通高中化学课程标准(2017年版)》对“变化观念与平衡思想”素养的内涵描述和水平划分为例,开发高中生“变化观念与平衡思想”素养测试题,运用Rasch测量模型对工具的质量进行检验、优化并加以运用。结合测试数据调查了学生“变化观念与平衡思想”素养水平现状,分析了研究被试能力值的学校差异和班级差异,并对该素养培养提出建议。     

初中生化学信息加工能力的测查研究*

“化学信息加工”贯穿于化学学习活动的全过程,是化学学习能力的核心成分。基于Rasch模型原理,对“化学信息加工能力”进行了水平建构、测验工具的开发及优化、能力测验及数据分析。研究显示,测验所获数据符合Rasch模型预期,测验工具具有良好的区分度和信度。依据测验数据,展示了九年级学生“化学信息加工能力”的水平分布,并提出了基于化学信息加工能力的教学建议。     

Determination of the enthalpy of fusion of K<Subscript>3</Subscript>TaO<Subscript>2</Subscript>F<Subscript>4</Subscript> and KTaF<Subscript>6</Subscript>

Areas of fusion and crystallization peaks of K₃TaO₂F₄ and KTaF₆ were measured using the DSC mode of a high-temperature calorimeter (SETARAM 1800 K). On the basis of these quantities, considering the temperature dependence of the calorimeter sensitivity, values of the fusion enthalpy of K₃TaO₂F₄ at the fusion temperature of 1181 K of (43 ± 4) kJ mol⁻¹ and of KTaF₆ at the fusion temperature of 760 K of (8 ± 1) kJ mol⁻¹ were determined.     

“蒸馏酒”还是“发酵酒”——对《科学史导论》中“spirits” 和“distillation”的再思考

科学史奠基者乔治·萨顿在《科学史导论》第二卷的第一部分对我国宋代酿酒著作《北山酒经》予以了简要描述,出现了“spirits”“distillation”等字样;而《北山酒经》被众多学者认为其描述对象是发酵酒(黄酒)。本文从东西方蒸馏技术和相关著作的文本分析对《科学史导论》中提及的蒸馏技术和蒸馏酒存在的可能性提出了质疑。     

Physicochemical foundations of synthesis of new ferromagnets from chalcopyrites A<Superscript>II</Superscript>B<Superscript>IV</Superscript>C<Stack><Subscript>2</Subscript><Superscript>V</Superscript></Stack>

The results of studying phase equilibria of ternary A^IIB^IVC^V systems have been reported. Physicochemical foundations have been developed for the synthesis of new ferromagnets with Curie temperatures above room temperature structurally compatible with basic semiconducting materials. Methods of synthesis and physicochemical properties of manganese-doped A^IIB^IVC₂^V ferromagnets have been described. The results of theoretical simulation of magnetic properties have been considered and basic approaches to the explanation of the emergence of ferromagnetism in A^IIB^IVC₂^V doped with 3d metals have been surveyed. The most promising ways to produce and study dilute magnetic semiconductors as spintronics materials have been presented.     

2,4‐Di­nitro­phenyl­hydrazones of 2,4‐di­hydroxy­benz­aldehyde, 2,4‐di­hydroxy­aceto­phenone and 2,4‐di­hydroxy­benzo­phenone

In 2,4‐di­hydroxy­benz­aldehyde 2,4‐di­nitro­phenyl­hydrazone N,N‐di­methyl­form­amide solvate {or 4‐[(2,4‐di­nitro­phenyl)­hydrazono­methyl]­benzene‐1,3‐diol N,N‐di­methyl­form­amide solvate}, C₁₃H₁₀N₄O₆·C₃H₇NO, (X), 2,4‐di­hydroxy­aceto­phenone 2,4‐di­nitro­phenyl­hydrazone N,N‐di­methyl­form­am­ide solvate (or 4‐{1‐[(2,4‐di­nitro­phenyl)hydrazono]ethyl}benzene‐1,3‐diol N,N‐di­methyl­form­amide solvate), C₁₄H₁₂N₄O₆·C₃H₇NO, (XI), and 2,4‐di­hydroxy­benzo­phenone 2,4‐di­nitro­phenyl­hydrazone N,N‐di­methyl­acet­amide solvate (or 4‐­{[(2,4‐di­nitro­phenyl)hydrazono]phenyl­methyl}benzene‐1,3‐diol N,N‐di­methyl­acet­amide solvate), C₁₉H₁₄N₄O₆·C₄H₉NO, (XII), the molecules all lack a center of symmetry, crystallize in centrosymmetric space groups and have been observed to exhibit non‐linear optical activity. In each case, the hydrazone skeleton is fairly planar, facilitated by the presence of two intramolecular hydrogen bonds and some partial N—N double‐bond character. Each molecule is hydrogen bonded to one solvent mol­ecule.     

Projection of the liquidus surface of the Sb<Subscript>2</Subscript>Te<Subscript>3</Subscript>-Gd<Subscript>2</Subscript>Te<Subscript>3</Subscript>-Bi<Subscript>2</Subscript>Te<Subscript>3</Subscript> system

Phase equilibria in the Sb₂Te₃-Gd₂Te₃-Bi₂Te₃ ternary system have been studied using differential thermal analysis, namely, X-ray powder diffraction, microstructure examination, thermodynamic analysis, and microhardness and alloy density measurements. Phase diagrams of some polythermal joins and liquidus surface have been constructed. The regions of primary crystallization of phases and the coordinates of all invariant and univariant equilibria in the system under investigation have been established.     

Crystal structure of the synthetic analog of radtkeite Hg<Subscript>3</Subscript>S<Subscript>2</Subscript>Cl<Subscript>1.00</Subscript>I<Subscript>1.00</Subscript>

The results of structural studies of the synthetic analog of the radtkeite mineral Hg₃S₂Cl_1.00I_1.00 are analyzed. The crystal structure of the compound has been refined; the unit cell parameters are a _m = 16.827(4) , b _m = 9.117(1) , c _m = 13.165(5) , = 130.17(2)°, V = 1543.3(8) ³, space group C2/m, Z = 8, R = 0.0527. A possible transition a ₀ = a _m; b ₀ = a _m + 2c _m; c ₀ = –b _m to the pseudo-orthorhombic F cell previously determined for radtkeite, where one of the angles ( ₀ ) is slightly different from 90° (89.55°), has been found. Each sulfur atom in the structure is bonded to three mercury atoms, forming SHg₃ umbrellas with distances 2.240(6) –2.474(8) and angles HgSHg 94.7(2)°–102.9(2)°. The SHg₃ fragments are linked through Hg vertices to form corrugated [Hg₁₂S₈] layers. The halogen atoms lie inside and between the [Hg₁₂S₈] layers; the distances are Hg-Cl and Hg-I 2.783(7) , 2.961(7) , and 3.083(4) –3.311(3) , respectively.Original Russian Text Copyright © 2004 by N. V. Pervukhina, S. V. Borisov, S. A. Magarill, D. Yu. Naumov, V. I. Vasiliev, and B. G. NenashevTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 755–758, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Determination of the enthalpy of fusion of K<Subscript>3</Subscript>NbO<Subscript>2</Subscript>F<Subscript>4</Subscript>

Areas of fusion and crystallization peaks of K₃NbO₂F₄ were measured using the DCS mode of a high-temperature calorimeter (SETARAM 1800 K). On the basis of these quantities, considering the temperature dependence of the calorimeter sensitivity, the value of the fusion enthalpy of K₃NbO₂F₄ of (98 ± 6) kJ mol⁻¹ was determined at the fusion temperature of 1257 K.     

Structure of Zn<Subscript>3</Subscript>P<Subscript>2</Subscript>

The structure of Z_n3P₂ (P 4₂/nmc, a = b = 8. 0785 Å, c = 11. 3966 Å) was solved and refined to R = 3. 2% in a precision X-ray diffraction experiment (λ-MoK _a, graphite monochromator on a primary beam, 27,496 reflections) . Interatomic distances and bond angles have been determined. The fcc lattice of the structure is built from phosphorus atoms, and the zinc atoms occupy 3/4 of all tetrahedral voids; the structure is described by two equivalent models where 1/4 occupied (by zinc atoms) and 1/4 vacant voids change places. The zinc atoms that occupy the voids following the diamond principle do not change places.Original Russian Text Copyright © 2004 by I. E. Zanin, K. B. Aleinikova, M. M. Afanasiev, and M. Yu. Antipin__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 5, pp. 889–892, September–October, 2004.     

Calculations of thermodynamic stability of CpCoC<Subscript>2</Subscript>B<Subscript>9</Subscript>H<Subscript>11</Subscript> cobaltacarborane isomers

Quantum-chemical calculations of the geometry and energies of nine possible isomers of 12-vertex cobaltacarborane CpCoC₂B₉H₁₁ (1) were carried out by the DFT method (PBEPBE/DGDZVP/DGA1). Thermodynamic stability of the isomers increases with increasing distance between the carbon atoms in the cage and is virtually independent of the position of the CpCo vertex. The relative stabilities of the 1,2,3-(17.57 kcal mol⁻¹), 1,2,4-(3.72 kcal mol⁻¹), and 1,2,9-isomers of 1 (0 kcal mol⁻¹) are similar to the corresponding values for the ortho (17.61 kcal mol⁻¹), meta (3.21 kcal mol⁻¹), and para isomers (0 kcal mol⁻¹) of carborane C₂B₁₀H₁₂. The results of the present study confirm a close similarity of the CpCo and BH fragments in metallacarborane chemistry. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1557–1559, July, 2005.     

Mechanism and kinetics of formation of La<Subscript>2</Subscript>SrFe<Subscript>2</Subscript>O<Subscript>7</Subscript> and Nb<Subscript>2</Subscript>SrFe<Subscript>2</Subscript>O<Subscript>7</Subscript>

Phase formation processes in the systems Ln₂O₃-SrO-Fe₂O₃ (Ln = La, Nd) in air in the temperature range 1200–1500°C were studied. The synthesis of the complex ferrites La₂SrFe₂O₇ and Nb₂SrFe₂O₇ involves the formation of the intermediate compounds LnFeO₃ and LnSrFeO₄ and occurs by the same mechanism as the synthesis of the corresponding aluminates, but much faster.